My current brewing set up is as follows: 2 Fermenter's Favorite 10 gallon all grain coolers hot liquor tank and mash tun, 15 gallon Megapot boil kettle, Edelmetal Bru Burner, and a homemade gravity stand. I usually brew 10 gallon batches with 12 to 13 gallons pre boil. My local hardware store has a killer deal on 15,20, and 25 gallon aluminum pots. I was thinking of picking up a couple to replace my coolers and outfit them with ball valves and thermometers etc. The main reason is because I currently can only do single infusion mash recipes. Any luck with aluminum anyone? Or should I stick with my coolers until I save my pennies for all stainless gear?
You can certainly use aluminum for a mash tun and do a direct fired set up. It comes down to whether or not you like that process. I have a direct fired stainless steel mash tun. I use a false bottom and a pump to constantly recirculate the wort through the mash. This keeps things moving when I am applying heat and prevents scorching or overheating the wort at the bottom of the mash. It works pretty well. But there are draw backs.
For one, you have to babysit this thing the whole mash period. And if you don't have some sort of automated temperature and burner ignition system, you have to manually fire the tun off and on occasionally to keep the temps up. Aluminum will give up heat faster that my stainless as well, so you'll need to cycle on and off quite a bit.
I have noticed that if the temp gets to far away from target and you try and apply too much heat then you end up with screwy mash profiles and sometimes poor attenuation due to degraded enzymes and poor conversion.
Its something worth trying out, but I am currently thinking of going back to the cooler set up just to stop working so hard during the mash. And I can do something else while the mash is going in my cooler.
Just food for thought.
I personally would not use an aluminum kettle for a mash tun.
Aluminum transfers heat too well. While that's great for a boil kettle or hlt, a mash tun needs to hold heat. Even if well insulated it will lose much more heat than its stainless steel counter part and way more than a cooler style tun.
Aluminium is not used commercially as the risks of contaminating the work with aluminium, CIP with Caustic and Acid destroys aluminium. Likewise you do not want to contaminate your wort/beer. If the pH of your wort was to drop below ~4.5 then it would risk affecting the stability of the oxide layer.
They would be fine to use for HLT or CLT. ie anything that does not come in contact with the wort/beer.
I would personally wait and get the lovely shiny 304 or 316 SS, that will last you a lifetime.